Help, need info on installing new windows in 1981 Telstar

[Cynthia]

Hi, I am a new owner of a 1981 Telstar 26. I bought the boat, stripped, ready for refurbishing. The windows were old, cracked, so putting in new polycarbonate windows. My question is, the old windows were screwed in, (not sure they were the original windows). My questions are: 1. Should I fill the old holes (too hard to match) and screw in the new windows as well, and if so, with what sealer? 2. Or should I fill the holes and then adhesive on the new windows, and with what adhesive? And then do I still need a sealer around the windows? I read there are new adhesives on the market. Please any, all, advice appreciated. The polycarbonate windows are not cheap; I need installation to work. Thank you. - Cindy

[JoeS.]

Hi Cynthia. Welcome to the Association and congratulations for saving one of the few US-made Telstars. If it's a 1981 then it's called a Telstar 8m. Mine is s/n 256 - what's your serial number and whereabouts are you located?

Back in the mid-80's I made wooden window frames for the inside and installed polycarbonate windows onto Sika 295 IIRC after prepping the surface, but for backup did screw them into the wood frame (have brass inserts) with spacer washers between the polycarbonate and the fiberglass to create a gap for the adhesive/sealant to provide some flexibility. Replaced the windows just before my Alaska trip in 1998 and they're still on the boat but definitely need replacement. That's 40-year-old technology.

I haven't done my homework yet to see what the modern techniques are. One solution I've seen is to use adhesive foam tape such as 3M VHB, but need to verify compatibility with polycarbonate vs. acrylic, carefully follow surface preparation instructions, and then figure out how to apply it (seems to me you have one shot at it) and what to use to seal around the edge.

HTH

[bretnvalerie]

We have used Dow 795 and 3M VHB tape on a Macgregor 26x replacement window, and it worked great. 3M 4200 is some awesome stuff. Please do some research to make sure these are compatible with the window material.
Goodluck

[Cynthia]

Hi Cynthia. Welcome to the Association and congratulations for saving one of the few US-made Telstars. If it's a 1981 then it's called a Telstar 8m. Mine is s/n 256 - what's your serial number and whereabouts are you located?

Back in the mid-80's I made wooden window frames for the inside and installed polycarbonate windows onto Sika 295 IIRC after prepping the surface, but for backup did screw them into the wood frame (have brass inserts) with spacer washers between the polycarbonate and the fiberglass to create a gap for the adhesive/sealant to provide some flexibility. Replaced the windows just before my Alaska trip in 1998 and they're still on the boat but definitely need replacement. That's 40-year-old technology.

I haven't done my homework yet to see what the modern techniques are. One solution I've seen is to use adhesive foam tape such as 3M VHB, but need to verify compatibility with polycarbonate vs. acrylic, carefully follow surface preparation instructions, and then figure out how to apply it (seems to me you have one shot at it) and what to use to seal around the edge.

HTH Hi Joe S. Thank you so much for the info on the windows, I was on vaca and just returned. I am in Kansas (yes, we have lakes and good wind!) I looked up her specs, She's a MK III, 26.3, one of the last USA boats built by Tony before the factory burned. Largest cabin Tony build with 5 berths and a 5ft 9 headroom. Her serial is PCI002500281. From the pics I have, I think she was first launched in Alaska, but sailed in Wisconsin for 20 years, roughly 80s-2000s. She has been stored inside ever since, and is in excellent condition for her age. I bought her in 2021, stripped, ready to repaint, varnish etc. She sits on a custom made trailer. I have been working on her for 2 1/2 years in my barn, hand painted her inside and out, 4 coats, outside. I've always sailed Hobies and wanted a tri, but with my age, I now want something less wide. Long story short, I've decided to sell her next spring once I get the windows in and wood back on. She will be ready to fly across the water for the next new owner. Again, thanks so much for the info. - Cindy

[Cynthia]

We have used Dow 795 and 3M VHB tape on a Macgregor 26x replacement window, and it worked great. 3M 4200 is some awesome stuff. Please do some research to make sure these are compatible with the window material.
Goodluck

Bret n Valerie, thanks so much on the info for window replacement. I was on vaca and just returned. Much appreciated. - Cindy